Carl tiialacker



(No Model.)

- "C. THA'LACKER.

ELEGTRIU' SAFETY FUSE.

1%.. 502,541. Patented Aug. 1,1893.

UNITED STATES PATENT OFFICE.

CARL THALACKER, OF CHARLOTTENBURG, ASSIGNOR TO SIEMENS do IIALSKE, OF BERLIN, GERMANY.

ELECTRIC SAFETY-FUSE.

SPECIFICATION forming part of Letters Patent No. 502,541, dated August 1, 1893. Application filed May 18, 1893. $erial No. 474,665. (No model.)

To aZZ whom it may concern:

Be it known that I, CARL THALACKER, a subject of the King of Saxony, residing at the city of Oharlottenburg, Kingdom of Prussia, German Empire, have invented new and useful Improvements in Electric Safety-Fuses, of

which the following is a specification.

M y invention relates to electric safety fuses. Safety fuses as heretofore constructed have consisted of a strip of fusible metal inserted 1 between the divided ends of an electrical con reliable, as their fusing point is spectively, top and ductor. Such fuses are commonly unprotected by any covering. Hence, when they are blown, the metal of the fuse strip is spatter-ed over the surrounding parts, and it is not unusual for an arc to form between the remaining portions of the strip or the terminals of the conductors to which the strip is w.th a strip of fusible metal, completely inclosed in a non-conducting box or case, an auxiliary fusible strip so located and connected as to be seen at all times, and which will be destroyed when the main fuse, which .is out of sight, is blown.

"Referring to the accompanying drawings which illustrate my invention, similar reference numerals indicate like parts.

Figure 1 is a front elevation. Fig. 2 is a longitudinal section 011 the line 00, c of Fig. 1. Fig. 3 is a transverse section on the line y, y of Fig. 1. Fig. i is a perspective view showing the separate parts and their relation to J1 l1 other.

In the drawings, 5 indicates the main fusible strip made of any suitable material, which will melt at a determined temperature; 6 and 7, terminal pieces to which the strip is connected by crimping or otherwise; 8 and sxbrebottom portions of a ox or cover for inclosing the main strip. {The top portion 8 has formed through it an opening 9. The box may be made of any suitable non-conducting material, such as wood, vulcanite, compressed paper, &c.

10 and 10 are thin strips of wood, vulcanite, indurated paper, or similar material; one of which is placed over, and the other under the main fusible strip 5 so as to, in connection with the main strip, completely fill the cavity of the inclosing case. Arranged over the portion 10 is what I term the auxiliary fusible strip 11, which may be made of any suitable material which will fuse at the same temperature as the main strip, or be fused when the main strip is fused; a thin sheet of tin-foil I find answers the purpose as well as anything else. A part of this strip, it will be observed, lies under and across the opening 5) in the upper portion 8 of the case, and can be seen plainly through the opening.

12 are screws for securing the parts of the box or casing together, but other devices may be used for this purpose, and the configuration given the box or casing may be modified to suit the position in which the fuse is to be I placed.

I do not limit myself in any wise to the shape of the particular parts specified.

The operation of my improved fuse is readily understood. \Vhen the main fuse is blown, the auxiliary fuse islikewise blown; the main fuse, however, being completely incased within the protecting cover, the material of which it is made cannot scatter, nor can an are be formed, and the action of the fuse is no longer affected by variation in temperature. At the same time the condition of the main fuse will always beindicated by the con dition of the auxiliary fuse, as seen through the opening in the casing.

Having thus described claim- 1. In an electric safety fuse, the combination of a main safety fuse, an auxiliary safety fuse, and a box or casing completely enveloping the main fuse, but so constructed as to permit the condition of the auxiliary fuse to be seen.

2. In an electric safety fuse, the combination of a main fuse,

my invention, I

an auxiliary fuse, and a casing completely enveloping the main fuse,

but only partially enveloping the= auxiliary material, and an inclosing' casing, said casing fuse. provided with an opening through its tar 3. In an. electric safety fuse, the combinaportion whereby the condition of the auxi tion of a main fuse, an auxiliary fuse, and a iary fuse may be observed. 5 detachable casing therefor, said casing Wholly In testimony whereof I affix my signature in 1 surrounding the main fuse and partially surthe presence of two witnesses.

rounding the auxiliary fuse. CARL T-l-IALAOKER.

4. In an electric safety fuse, the combina- Witnesses: tion of a main fuse, an auxiliary fuse, over- OSCAR BIELEFELD,

[O lying and underlying portions of insulating MAX lVAG-NER.

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